Renault Megane 02 reg Coupe speedo stopped working? Help plz

[nox]

Hi all,

Please can someone help with advice on the above, i am hoping someone may have an idea of what the problem may be, i've tried to book it into the local garage but they have no space till Thursday.
I have an 2002 reg megane coupe and this morning the speedometer stopped working, including the total mileage recorder freezing at 83k, trip mileage recorder, average consumption and the rest on that led pannel, the one thing still working is the fuel used screen.... The rest of the dash is all working fine tho including the RPM.
Bit more background info -
When driving today it sounded like there was water under the passenger footwell (thats probably a bit overstated but its the only way i can explain it.) when driving/stopping it sounded like the water or whatever would be swishing around. It might always be there and i only noticed it today, it is very quiet.
Lastly i had the brake discs, pads etc changed last weekend on front and back.
Any suggestions or questions would be great.

Thanks,

Paul

[Mr Jenks]

Speedo info is generated by ABS system. Have seen several with corroded wiring from ABS to dashboard, normally around chassis rail on O/S by timing cover.